Refrigerating system and method of charging the same



E. J. FISHER 2,049,364

REFRIGERATING SYSTEM AND METHOD OF CHARGING THE SAME July 28, 1936.

Filed Aug. 1, 1934 Inventor:

w w mar 1am t m m .6 e v E 4Q frigerator cabinet Patented July 28, 1936 PATENT OFFICE REFRTGERATING SYS CHARGING THES TEM AND METHOD OF AME Everett J. Fisher, Schenectady, N. Y., assignor to General New York Electric Company, a corporation of Application August 1, 1934, Serial No. 737,942

5 Claims.

My invention relates to refrigerating systems and to methods for charging such systems.

and refrigerant pump are on the high pressure side, and the evaporator is on the low pressure side of'the system. These systems are commonly charged with refrigerant by first evacuating the system other gases and then admitting to the high pressure side and to the low pressure side. In order to evacuate both sides of the system and to admit refrigerant evacuating and charging.

Further objects and advantages of my invention will become apparent as the following description proceeds, and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of my invention reference may be had to the accompanying drawing, the single figure of which is a side elevation partly in section of a refrigerating machine which has been charged in accordance with my invention.

Referring to the drawing I have shown a recomprising an outer wall I I and an inner liner l2 supported within the wall ll above a partition l3 extending across the cabinet, heat insulation l4 being arranged between the walls about the inner liner l2 in order to prevent the leakage of heat into a cooling compartment l5 formed by the liner l2. A thermally insulated door I6 is provided to close the cooling compartment, and an inverted L-shaped evaporator I1 is secured to the liner I 2 within the compartmet I5 in order to cool the same. The evaporator is provided with a header l8 embedded in the insulation l4 and with an upper connection l9 and a lower connection providing communication withthe header so that the liquid refrigerant may circulate through the evaporator and the header. This L-shaped evaporator construction and the arrangement of the header is shown and described in a co-pending application of Christian Steenstrup, Serial No. 733,044, filed June 29, 1934, and assigned to the General Electric Company, the assignee of my present invention. I, therefore, do not claim anything described or claimed in the said Steenstrup appli cation which is to be regarded as prior art with respect to my present application, my invention relating to refrigerating systems and to a method for charging the same. In order to supply refrigerant to the evaporator I 1, I provide a source of refrigerant comprising a motor and a com pressor arranged within a closed casing 2| mounted in the lower part of the cabinet I0 below the partition l3. Gaseous refrigerant is compressed by the compressor and is discharged through a connection 38 from which it flows through a condenser comprising conduits 22 and 23 connected by a conduit 24. Conduits 22 and 23 are secured in heat exchange relation with the outer wall ll of the refrigerator cabinet and are cooled by circulation of air over the outer wall. This condenser construction wherein the conduits are secured to the outer wall of a refrigerator cabinet is shown and described in a copending application of Christian Steenstrup, Serial No. 554,623, filed August 3, 1931, and assigned to the General Electric Company, assignee of my present invention. I do not, therefore, herein claim anything described or claimed in the said Steenstrup application which is to be regarded as prior art with respect to this present application, my invention relating to refrigerating systems and a method of charging them.

The refrigerant discharged from the compressor is condensed and liquefied within the condenser conduits 22 and 23 and flows through a connection 25 to a receiver or float valve chamber 26, and when a predetermined quantity of liquid refrigerant has collected in the chamber 26 a float 21 therein rises and lifts a needle valve 28 from its seat 29 and liquid refrigerant is discharged through a connection 30 and enters the evaporator IT. The refrigerant is vaporized upon the absorption of heat from .the compartment l 5 and the vapor collects within the header l8 above the level of liquid refrigerant therein and is withdrawn therefrom through a suction conduit 3| and returns to the casing 2|, which is on the low side of the compressor. The refrigerant is thus circulated in a closed cycle through the refrigerating system. It will be evident from the foregoing that the float valve chamber or receiver 26 and the condenser \are on the high pressure side of the refrigerating system, while the evaporator and header and the casing 2| are on the low pressure side of the system, the pressure difference being maintained by the valve 28 and the discharge valve of the compressor.

In order to charge a refrigerating system of the type shown, it is necessary'first to drive out all gases from the system as by evacuating the system while heated in an oven or by some other suitable arrangement. When the system has been evacuated a predetermined charge of refrigerant may be admitted thereto. It willbe evident, however, that in order to effectively exhaust and charge both the high and low pressure the system, it is necessary to connect both sides to the vacuum pump and to the source of refrigerant charge. This is commonly accomplished by providing a connection in the low pressure side and another connection in the high pressure side, charging both sides simultaneously through these connections, and then sealing off both connections.

In accordance with my invention, I provide a single connection 32 to the system and provide a conduit 36 affording communication between the high and low pressure sides to by-pass the valve, then evacuate the system, and introduce the charge. When I have charged the system with refrigerant in this manner, I close the connection 32 and then close the by-pass 36 between the high and low pressure sides by pinching the same at 31.

In the refrigerating machine illustrated I provide a connection 32 within which is a needle valve 33 which seats in the mouth of a duct 33. When the valve 33 is unscrewed so that it is no longer seated, a groove 33a, in the side thereof provides communication with the float chamber 26. A vacuum pump or a suitable source of refrigerant charge as required may be attached to the connection 32, a cap 35 being removed for this purpose. In order to provide communication between the high and low pressure sides of the system during evacuation and charging, I provide a conduit 36 connecting the float -valve chamber'26 and the upper portion of the header 18. The cond 't 36 as shown extends outside the insulation l4 through the partition I3 leaving a portion extending into the lower compartment of the cabinet and accessible therethrough'. In order to chargethe refrigerating system I first attach a vacuum pump to the connection 32 and evacuate the system, the high and low pressure sides being connected together, and both being exhausted thereby; Evacuation of the system is made complete by heating the refrigerating machine in a suitable oven during operation of the vacuum pump. When a suitable degree of vacuum has been attained, I close the valve 33, disconnect the vacuum pump and attach a suitable source of refrigerant to the connection 32, then open the valve 33 to admit liquid refrigerant'to the refrigerating system through the float valve chamber 26. The refrigerant vaporizes in part and fills the system, liquid refrigerant collecting in the evaporator and float valve chamber 26. When a predetermined charge has been admitted, I close the valve33 and thereby seal the system. I then close the conduit 36 in any suitable manner such as by pinching the portion extending beyond .the thermal insulation M as shown at 31. This cuts off communication between the high and low pressure sides of the system and places the refrigerating system in readiness for operation, the

sides of.

.said low pressure pressure difference between the high and low pressure sides of the system being built up by the compressor within the casing 2!. It will thus be seen that I have provided a closed cycle hermetically sealed refrigerating machine which is especially adapted for household use since all of the final connections between the various elements of the machine are sealed and consequently cannot be readily altered or tampered with by an inexpert user.

While I have described my invention in connection with a houshold refrigerating machine of the compression type, I do not desire my invention to be limited to the specific arrangement described, and I, therefore, intend in the appended claims to cover all modifications which fall within the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a refrigerating system including a compressor, a flooded evaporator, a liquid receiver, a valve between said receiver and said evaporator, and a by-pass around said valve, the method of charging said system with refrigerant which comprises evacuating'said system and admitting a charge of liquid refrigerant to said system with said by-pass open, and sealing said system and closing said by-pass.

2. In a refrigerating system including a compressor, a flooded evaporator having a header, a liquid receiver, a valve between said receiver and said evaporator, and a by-pass conduit around said valve connecting said receiver and said header, the method of charging said system which comprises evacuating said system and introducing a charge of liquid refrigerant into said system with said by-pass open, and sealing said system and sealing said conduit to prevent communication therethrough between said header and said receiver.

3. A refrigerating system having a high pressure side and a low pressure side and a compartment to be cooled, heat insulation surrounding said compartment, means including an evaporator on said low pressure side for cooling said compartment, a refrigerant receiver on said high pressure side and embedded within said heat insulation, means for pumping refrigerant from said low pressure side to said high pressure side, means including a valve arrangement between said receiver and said evaporator for controlling the flow of refrigerant from said high pressure side to said low pressure side, means including a conduit connecting said receiver and said evaporator having a portion extending outside said heat insulation for providing communication between said high andlow pressure sides when charging said system with refrigerant, and means restricting the portion of said conduit extending outside said heat insulation for closing said conduit when said system has been charged with refrigerant.

4. A refrigerating system having a high pressure side and a low pressure side and a refrigerator cabinet including a plurality of compartments, heat insulation surrounding one of said compartments, means including an evaporator on side for cooling said last mentioned compartment, a refrigerant receiver on said high pressure side; means located in another of said compartments for pumping refrigerant from said low pressure side to said high pressure side, means including a valve arranged between said receiver and said evaporator for controlling the flow of refrigerant from said'high pressure side'to said low pressure side, means including a conduit connecting said receiver and said evaporator having a portion extending through one of said compartments for providing communication between said high and low pressure sides when charging said system with refrigerant, and means permanently sealing said portion of said conduit for closing said conduit when said system has been charged with refrigerant.

5. A refrigerating system having a high pressure side and a low pressure side and a refrigerator cabinet provided with a plurality of compartments, heat insulation surrounding one of said compartments, means including an evaporator on said low pressure side for cooling said one compartment, a refrigerant receiver on said high pressure side and embedded within said heat insulation, means located in another of said compartments for pumping refrigerant from said low pressure side to said high pressure side, means including a valve arrangement between said receiver and said evaporator for controlling the flow of refrigerant from said high pressure side to said low pressure side, means including a conduit connecting said receiver and said evaporator having a portion extending outside said heat insulation and through said last mentioned compartment for providing communication between said high and low pressure sides when charging said system with refrigerant, and means permanently sealing said portion of said conduit for closing said conduit when said system has been charged with refrigerant.

EVERETT J. FISHER. 

